// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/json/json_file_value_serializer.h"

#include "base/files/file_util.h"
#include "base/json/json_string_value_serializer.h"
#include "base/logging.h"
#include "build/build_config.h"

using base::FilePath;

const char JSONFileValueDeserializer::kAccessDenied[] = "Access denied.";
const char JSONFileValueDeserializer::kCannotReadFile[] = "Can't read file.";
const char JSONFileValueDeserializer::kFileLocked[] = "File locked.";
const char JSONFileValueDeserializer::kNoSuchFile[] = "File doesn't exist.";

JSONFileValueSerializer::JSONFileValueSerializer(
    const base::FilePath& json_file_path)
    : json_file_path_(json_file_path)
{
}

JSONFileValueSerializer::~JSONFileValueSerializer()
{
}

bool JSONFileValueSerializer::Serialize(const base::Value& root)
{
    return SerializeInternal(root, false);
}

bool JSONFileValueSerializer::SerializeAndOmitBinaryValues(
    const base::Value& root)
{
    return SerializeInternal(root, true);
}

bool JSONFileValueSerializer::SerializeInternal(const base::Value& root,
    bool omit_binary_values)
{
    std::string json_string;
    JSONStringValueSerializer serializer(&json_string);
    serializer.set_pretty_print(true);
    bool result = omit_binary_values ? serializer.SerializeAndOmitBinaryValues(root) : serializer.Serialize(root);
    if (!result)
        return false;

    int data_size = static_cast<int>(json_string.size());
    if (base::WriteFile(json_file_path_, json_string.data(), data_size) != data_size)
        return false;

    return true;
}

JSONFileValueDeserializer::JSONFileValueDeserializer(
    const base::FilePath& json_file_path,
    int options)
    : json_file_path_(json_file_path)
    , options_(options)
    , last_read_size_(0U)
{
}

JSONFileValueDeserializer::~JSONFileValueDeserializer()
{
}

int JSONFileValueDeserializer::ReadFileToString(std::string* json_string)
{
    DCHECK(json_string);
    if (!base::ReadFileToString(json_file_path_, json_string)) {
#if defined(OS_WIN)
        int error = ::GetLastError();
        if (error == ERROR_SHARING_VIOLATION || error == ERROR_LOCK_VIOLATION) {
            return JSON_FILE_LOCKED;
        } else if (error == ERROR_ACCESS_DENIED) {
            return JSON_ACCESS_DENIED;
        }
#endif
        if (!base::PathExists(json_file_path_))
            return JSON_NO_SUCH_FILE;
        else
            return JSON_CANNOT_READ_FILE;
    }

    last_read_size_ = json_string->size();
    return JSON_NO_ERROR;
}

const char* JSONFileValueDeserializer::GetErrorMessageForCode(int error_code)
{
    switch (error_code) {
    case JSON_NO_ERROR:
        return "";
    case JSON_ACCESS_DENIED:
        return kAccessDenied;
    case JSON_CANNOT_READ_FILE:
        return kCannotReadFile;
    case JSON_FILE_LOCKED:
        return kFileLocked;
    case JSON_NO_SUCH_FILE:
        return kNoSuchFile;
    default:
        NOTREACHED();
        return "";
    }
}

std::unique_ptr<base::Value> JSONFileValueDeserializer::Deserialize(
    int* error_code,
    std::string* error_str)
{
    std::string json_string;
    int error = ReadFileToString(&json_string);
    if (error != JSON_NO_ERROR) {
        if (error_code)
            *error_code = error;
        if (error_str)
            *error_str = GetErrorMessageForCode(error);
        return NULL;
    }

    JSONStringValueDeserializer deserializer(json_string, options_);
    return deserializer.Deserialize(error_code, error_str);
}
